Engine upgrade

[Peter Douglas W]

Without looking I would say HS4s.

[Peter Douglas W]

Without looking I would say HS4s

[johnnydog]

Assuming it is on HS4's, they were only fitted for a short period of time to the facelift 2000, before changing to HS6's. The 2000 engine on HS4's was considered to be a bit lacking in performance.
Are you certain that all the engine settings, including the carburettors are correctly set? There was quite a lot of changes in the engine settings around 1974 /5, and the workshop manuals, especially the non Triumph ones, didn't cover the changes as specifically as they perhaps should have done.

[Peter Douglas W]

I know the settings are correct. They were done using the Vacuum technique, compression tester, digital rev counter, little engine computor, strobe and a CO meter.
I have a lot of stuff from my TR6, head, Carbs 175CD Strombergs etc I wonder if it would be worth trying to fit them onto the 2000 engine.

[johnnydog]

Even though the face-lift ML engines with HS4's were never a ball of fire, they weren't as bad as you are portraying. The J type overdrive gearbox will make no difference to its performance Peter; in fact engaging overdrive in third and / or fourth will lower the engine revs and therefore will not accelerate quite as briskly as it would in direct drive.
Sticking my neck out, although you say the settings are correct, if your compressions are equal (more or less), valve clearances are correct, points ( if you have them) / ignition timing are correctly set, then I would argue that problem may lie with the carburation. I have found the best settings for the carbs is achieved by ear. Never had a great deal of success with gas / co analysers etc. Although the book / under bonnet sticker states the co reading should be between 2.5 and 4.5, I have found the engine runs at its sweetest at the upper end of those two readings.
If your car has electronic ignition, then the original settings are often different, ie timing, plug gaps etc.

[Peter Douglas W]

The compressions are good this was the reason for doing the head. Carbs are easy. I use the stethoscope and two little flow meters swaping them round in case they are not identical. Afterwards I do a CO check. I am from the old school a piece of hose in your ear is better than a meter. I set the points up using the dwell angle values. The dissy using the vacuum values. I think the poor quality of petrol is not helping. I tried the top quality fuel but hardly any difference, just the starting was quicker. What do you think to using TR6 bits?

[johnnydog]

I can't really give you any useful info on using the TR6 bits on your 2000 engine. I think someone such as Chris Witor would be one of the best people to ask, as he has played with performance enhancing modifications to the 2000 / 2500 range for many years.

[Alec]

Hello Peter,

putting a TR6 head on a 2000 engine needs a little arithmetic, as the TR engine is a 2.5 litre so 25% more volume. Quite what commpression you will get with a 2000 engine is possibly nowhere near what you might expect? You can skim the head once the chamber volume required is calculated. Off hand, I don't know about valve sizes etc and whether there is a gain there. It depends on how much you wnat to do?
Another factor is getting both carburation and distributor curve right.

Alec

[Peter Douglas W]

Alex you may be right I have no idea. As the bits are laying in the garage takins space, I just thought how about using them. If nobody has tried then I should firget it.